Add NTFS snapshot testing on Windows using isolated VHD volumes

test/snapcheck-ntfs.ps1

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+param(
+    [Parameter(Mandatory = $true)]
+    [ValidateSet("setup", "cleanup", "show")]
+    [string]$Action
+)
+
+$ErrorActionPreference = "Stop"
+
+$root = (Get-Location).Path
+$bench = Join-Path $root "bench"
+
+
+function Assert-Administrator
+{
+    $identity = [Security.Principal.WindowsIdentity]::GetCurrent()
+    $principal = New-Object Security.Principal.WindowsPrincipal($identity)
+
+    if (-not $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
+        throw "NTFS snapshot tests require Administrator privileges."
+    }
+}
+
+
+function Invoke-DiskPart
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [string[]]$Commands
+    )
+
+    $scriptPath = Join-Path $env:TEMP ("snapraid-diskpart-" + [Guid]::NewGuid().ToString() + ".txt")
+
+    try {
+        [System.IO.File]::WriteAllLines($scriptPath, $Commands, [System.Text.Encoding]::ASCII)
+
+        $output = & diskpart.exe /s $scriptPath 2>&1
+        $exitCode = $LASTEXITCODE
+
+        $output | ForEach-Object {
+            Write-Host $_
+        }
+
+        if ($exitCode -ne 0) {
+            throw "diskpart failed with exit code $exitCode."
+        }
+    }
+    finally {
+        Remove-Item -LiteralPath $scriptPath -Force -ErrorAction SilentlyContinue
+    }
+}
+
+
+function Get-MountedVolumeName
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]$MountPath
+    )
+
+    $mountArg = $MountPath.TrimEnd([char]92) + "\"
+    $output = & mountvol.exe $mountArg /L 2>$null
+    $exitCode = $LASTEXITCODE
+
+    if ($exitCode -ne 0) {
+        return $null
+    }
+
+    foreach ($line in $output) {
+        $value = "$line".Trim()
+
+        if ($value -match '^\\\\\?\\Volume\{[^}]+\}\\$') {
+            return $value
+        }
+    }
+
+    return $null
+}
+
+
+function Normalize-VolumeName
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]$VolumeName
+    )
+
+    return $VolumeName.Trim().TrimEnd([char]92)
+}
+
+
+function Setup-Volume
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [int]$Index
+    )
+
+    $mountPath = Join-Path $bench "snap$Index"
+    $vhdPath = Join-Path $bench "snap$Index.vhdx"
+    $markerPath = Join-Path $bench "snap$Index.volume"
+
+    if (Test-Path -LiteralPath $mountPath) {
+        throw "Mount path '$mountPath' already exists."
+    }
+
+    if (Test-Path -LiteralPath $vhdPath) {
+        throw "VHD '$vhdPath' already exists."
+    }
+
+    if (Test-Path -LiteralPath $markerPath) {
+        throw "Volume marker '$markerPath' already exists."
+    }
+
+    New-Item -ItemType Directory -Path $mountPath | Out-Null
+
+    $mountForDiskPart = $mountPath.TrimEnd([char]92) + "\"
+
+    Invoke-DiskPart @(
+        "create vdisk file=`"$vhdPath`" maximum=1024 type=expandable",
+        "select vdisk file=`"$vhdPath`"",
+        "attach vdisk",
+        "convert gpt",
+        "create partition primary",
+        "format fs=ntfs quick label=SNAPRAID$Index",
+        "assign mount=`"$mountForDiskPart`""
+    )
+
+    $volumeName = Get-MountedVolumeName $mountPath
+
+    if (-not $volumeName) {
+        throw "Unable to resolve the volume name mounted at '$mountPath'."
+    }
+
+    Set-Content -LiteralPath $markerPath -Value $volumeName -Encoding ASCII
+
+    Write-Host "Mounted NTFS test volume $volumeName at $mountPath"
+}
+
+
+function Remove-TestShadows
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]$VolumeName
+    )
+
+    $wanted = Normalize-VolumeName $VolumeName
+
+    $shadows = @(
+        Get-WmiObject -Class Win32_ShadowCopy |
+        Where-Object {
+            $_.VolumeName -and ((Normalize-VolumeName $_.VolumeName) -ieq $wanted)
+        }
+    )
+
+    foreach ($shadow in $shadows) {
+        Write-Host "Deleting VSS snapshot $($shadow.ID) from $VolumeName"
+        Remove-WmiObject -InputObject $shadow
+    }
+}
+
+
+function Cleanup-Volume
+{
+    param(
+        [Parameter(Mandatory = $true)]
+        [int]$Index
+    )
+
+    $mountPath = Join-Path $bench "snap$Index"
+    $vhdPath = Join-Path $bench "snap$Index.vhdx"
+    $markerPath = Join-Path $bench "snap$Index.volume"
+
+    if (Test-Path -LiteralPath $markerPath) {
+        $volumeName = (Get-Content -LiteralPath $markerPath -Raw).Trim()
+
+        if ($volumeName) {
+            Remove-TestShadows $volumeName
+        }
+    }
+
+    if (Test-Path -LiteralPath $vhdPath) {
+        Invoke-DiskPart @(
+            "select vdisk file=`"$vhdPath`"",
+            "detach vdisk noerr"
+        )
+
+        Remove-Item -LiteralPath $vhdPath -Force
+    }
+
+    if (Test-Path -LiteralPath $mountPath) {
+        Remove-Item -LiteralPath $mountPath -Recurse -Force
+    }
+
+    if (Test-Path -LiteralPath $markerPath) {
+        Remove-Item -LiteralPath $markerPath -Force
+    }
+}
+
+
+function Setup
+{
+    if (-not (Test-Path -LiteralPath $bench)) {
+        New-Item -ItemType Directory -Path $bench | Out-Null
+    }
+
+    Setup-Volume 1
+    Setup-Volume 2
+    Setup-Volume 3
+}
+
+
+function Cleanup
+{
+    $failed = $false
+
+    foreach ($index in 1..3) {
+        try {
+            Cleanup-Volume $index
+        }
+        catch {
+            Write-Warning "Cleanup of NTFS test volume $index failed: $($_.Exception.Message)"
+            $failed = $true
+        }
+    }
+
+    if ($failed) {
+        throw "Cleanup of one or more NTFS test volumes failed."
+    }
+
+    if (Test-Path -LiteralPath $bench) {
+        Remove-Item -LiteralPath $bench -Recurse -Force
+    }
+}
+
+
+function Show
+{
+    foreach ($index in 1..3) {
+        $mountPath = Join-Path $bench "snap$Index"
+        $snapshotPath = Join-Path $mountPath ".snapraid"
+        $markerPath = Join-Path $bench "snap$Index.volume"
+
+        Write-Host "${snapshotPath}:"
+
+        if (Test-Path -LiteralPath $snapshotPath) {
+            Get-ChildItem -LiteralPath $snapshotPath -Force |
+            Sort-Object Name |
+            ForEach-Object {
+                Write-Host "  $($_.Name)"
+            }
+        }
+        else {
+            Write-Host "  (missing)"
+        }
+
+        if (Test-Path -LiteralPath $markerPath) {
+            $volumeName = (Get-Content -LiteralPath $markerPath -Raw).Trim()
+            $wanted = Normalize-VolumeName $volumeName
+
+            Get-WmiObject -Class Win32_ShadowCopy |
+            Where-Object {
+                $_.VolumeName -and ((Normalize-VolumeName $_.VolumeName) -ieq $wanted)
+            } |
+            ForEach-Object {
+                Write-Host "  VSS $($_.ID)"
+            }
+        }
+    }
+}
+
+
+try {
+    switch ($Action) {
+        "setup" {
+            Assert-Administrator
+            Setup
+        }
+
+        "cleanup" {
+            Assert-Administrator
+            Cleanup
+        }
+
+        "show" {
+            Show
+        }
+    }
+}
+catch {
+    [Console]::Error.WriteLine("error: " + $_.Exception.Message)
+    exit 1
+}
+
+exit 0